refactor: migrate MICRO_PIP to fine-grained feature flags

Replace monolithic MICRO_PIP/PIP_MICRO with granular flags:

Feature flags (CMake options + platform auto-detection):
- PIP_NO_FILESYSTEM, PIP_NO_THREADS, PIP_NO_SOCKET
- PIP_NO_PROCESS, PIP_NO_DYNLIB, PIP_NO_FFT, PIP_NO_SERIAL

Embedded optimization flag:
- PIP_EMBEDDED (auto-set for Pico SDK and FreeRTOS)
  Controls buffer sizes, time stubs, terminal fallback, init stubs

Platform blocks in CMakeLists.txt:
- Pico SDK: auto-disables FS, PROCESS, DYNLIB, FFT, SERIAL;
  conditionally disables THREADS (no FreeRTOS) and SOCKET (no LWIP)
- FreeRTOS: auto-disables FS, PROCESS, DYNLIB, FFT, SERIAL;
  conditionally disables SOCKET (no LWIP)
- Android: auto-disables PROCESS, DYNLIB, FFT

Updated 96 files across libs/, utils/, tests/, and CMakeLists.txt.
Builds verified for Linux (547 tests pass) and Pico SDK (100%).
Removed all MICRO_PIP and PIP_MICRO references (0 remaining).

libs/main/io_utils/pibasetransfer.h

@@ -159,12 +159,14 @@ public:
 	//! \~russian Возвращает число байтов, уже обработанных в текущей сессии.
 	llong bytesCur() const { return bytes_cur; }
 
+#ifndef PIP_NO_THREADS
 	//! \~english Get diagnostics object
 	//! \~russian Получить объект диагностики
 	//! \~\return
 	//! \~english Diagnostic object reference
 	//! \~russian Ссылка на объект диагностики
 	const PIDiagnostics & diagnostic() { return diag; }
+#endif
 
 	//! \~english Returns the packet signature constant used by the protocol.
 	//! \~russian Возвращает константу сигнатуры пакета, используемую протоколом.
@@ -344,7 +346,9 @@ private:
 	CRC_16 crc;
 	int send_queue;
 	int send_up;
+#ifndef PIP_NO_THREADS
 	PIDiagnostics diag;
+#endif
 	PIMutex mutex_session;
 	PIMutex mutex_send;
 	PIMutex mutex_header;